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3D thermally induced analysis of annular plates of functionally graded materials

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Theoretical & Applied Mechanics Letters 2019年第5期9卷 297-301,I0004页

作者： Yun-fang yang Ding Chen Bo yang School of Civil Engineering and Architecture Zhejiang Guangsha College of Applied Construction TechnologyDongyang 322100China Department of Civil Engineering Zhejiang Sci-Tech UniversityHangzhou 310018China

Within the framework of three-dimensional elasticity theory,this paper investigates the thermal response of functionally graded annular plates in which the material can be transversely isotropic and vary along the thickness direction in an arbitrary *** generalized Mian and Spencer method is utilized to obtain the analytical solutions of annular plates under a through-thickness steady temperature *** present analytical solutions are validated through comparisons against those available in open literature.A parametric study is conducted to examine the effects of gradient distribution,different temperature fields,different diameter ratio and boundary conditions on the deformation and stress fields of the *** results show that these factors can have obvious effects on the thermo-elastic behavior of functionally gradient materials(FGM)annular plates.

关键词： Annular plate Functionally graded materials Thermo-elasticity Analytical solution

Near field 3-D imaging approach for joint high-resolution imaging and phase error correction

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Journal of Systems Engineering and Electronics 2017年第2期28卷 199-211页

作者： yang fang Baoping Wang Chao Sun Zuxun Song Shuzhen Wang School of Electronics and Information Northwestern Polytechnical University Xi’an 710072 China National Key Laboratory of Science and Technology on UAV Xi’an 710065 China School of Computer Science and Technology Xidian University Xi’an 710071 China

This paper combines compressed sensing (CS) imaging theory and range migration algorithm (RMA), and then proposes a near-field three-dimensional (3-D) imaging approach for joint high-resolution imaging and phase error correction. Firstly, a sparse measurement matrix construction method based on a logistic sequence is proposed, which conducts nonlinear transformation for the determined logistic sequence, making it obey uniform distribution, then conducts sign function mapping, and generates the pseudorandom sequence with Bernoulli distribution, thus leading to good signal recovery under down-sampling and easy availability for engineering realization. Secondly, in combination with the RMA imaging approach, the dictionary with all scene information and phase error correction is constructed for CS signal recovery and error correction. Finally, the non-quadratic solution model jointing imaging and phase error correction based on regularization is built, and it is solved by two steps - the separable surrogate functionals (SSF) iterative shrinkage algorithm is adopted to realize target scattering estimate; the iteration mode is adopted for the correction of the dictionary model, so as to achieve the goal of error correction and highly-focused imaging. The proposed approach proves to be effective through numerical simulation and real measurement in anechoic chamber. The results show that, the proposed approach can realize high-resolution imaging in the case of less data; the designed measurement matrix has better non-coherence and easy availability for engineering realization. The proposed approach can effectively correct the phase error, and achieve highly-focused target image. © 2017 Beijing Institute of Aerospace Information.

关键词： Compressed sensing Error correction Image reconstruction Iterative methods Linear transformations Mathematical transformations Signal reconstruction Signal sampling

On the non-local priors for sparsity selection in high-dimensional Gaussian DAG models

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Statistical Theory and Related Fields 2021年第4期5卷 332-345页

作者： Xuan Cao fang yang Division of Statistics and Data Science Department of Mathematical SciencesUniversity of CincinnatiCincinnatiOHUSA

We consider sparsity selection for the Cholesky factor L of the inverse covariance matrix in high-dimensional Gaussian DAG *** sparsity is induced over the space of L via non-local priors,namely the product moment(pMOM)prior[Johnson,V.,&Rossell,D.(2012).Bayesian model selection in high-dimensional *** of the American Statistical Asso-ciation,107(498),***://***/10.1080/01621459.2012.682536]and the hierarchi-cal hyper-pMOM prior[Cao,X.,Khare,K.,&Ghosh,M.(2020).High-dimensional posterior consistency for hierarchical non-local priors in *** Analysis,15(1),***://***/10.1214/19-BA1154].We establish model selection consistency for Cholesky fac-tor under more relaxed conditions compared to those in the literature and implement an efficient MCMC algorithm for parallel selecting the sparsity pattern for each column of *** demonstrate the validity of our theoretical results via numerical simulations,and also use further simulations to demonstrate that our sparsity selection approach is competitive with existing methods.

关键词： Bayesian DAG models non-local priors high-dimensional data posterior consistency graph selection

Simultaneous optimization of phononic and electronic transport in two-dimensional Bi2O2Se by defect engineering

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Science China(Information Sciences) 2023年第6期66卷 87-93页

作者： fang yang Hong Kuan NG Jing WU Yunshan ZHAO Junpeng LU School of Physics Southeast University Institute of Materials Research and Engineering Agency for ScienceTechnology and Research NNU-SULI Thermal Energy Research Center (NSTER) & Center for Quantum Transport and Thermal Energy Science (CQTES) School of Physics and TechnologyNanjing Normal University

Defect engineering represents one degree of freedom to tune the physical and chemical properties of two-dimensional (2D)***,we demonstrate that the thermal and electronic properties of 2D Bi2O2Se can be optimized simultaneously by introducing oxygen defects.2D Bi2O2Se and its oxygendeficient counterpart (Bi2Ox Se,x<2)can be controllably synthesized by the chemical vapor deposition(CVD)*** introducing oxygen defects,the thermal conductivity of 2D Bi2O2Se is reduced by nearly three times,achieving an extremely low thermal conductivity of 0.68±0.06 W/mK at room temperature via the thermal bridge *** low thermal conductivity is enabled by the scattering of phonons by targeting of high-,mid-,and low-frequency phonons due to oxygen defects,strong anharmonicity,and nanostructure boundaries,***,the mobility is also improved to 260–500 cm2·V-1·s-1and the usual polar optical phonon scattering in 2D Bi2O2Se is weakened owing to the introduction of oxygen *** results promise potential applications for thermoelectric design,nanoelectronics,and thermal barrier coating devices based on emerging 2D materials.

关键词： 2D Bi$_2$O$_2$Se thermal conductivity oxygens defects phonon scattering mobility

The progress of telestroke in China

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Stroke & Vascular Neurology 2017年第3期2卷 168-171页

作者： Gang Zhao Huan Huang fang yang Department of Neurology Xijing HospitalThe Fourth Military Medical UniversityXi'anChina

Stroke remains the leading cause of death in *** disparity of distribution in specialists and hospitals affects access to timely stroke ***,the use of telemedicine for stroke,may be the solution to access to stroke *** can improve the rate of successful intravenous thrombolysis and shorten the time to *** we review the progress of telestroke in China.

关键词： China. intravenous death

A New Generation of Intelligent Mapping and Remote Sensing Scientific Test Satellite Luojia-301

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Journal of Geodesy and Geoinformation Science 2023年第2期6卷 11-20页

作者： Deren LI Mi WANG fang yang State Key Laboratory of Information Engineering in Surveying Mapping and Remote SensingWuhan UniversityWuhan 430079China DFH Satellite Co. Ltd.Beijing 100094China

With the continuous improvement of the performance and the increasing variety of optical mapping and remote sensing satellites,they have become an important support for obtaining global accurate surveying and mapping remote sensing *** present,optical mapping and remote sensing satellites already have sub-meter spatial resolution capabilities,but there is a serious lag problem in mapping and remote sensing information *** is urgent to develop intelligent mapping and remote sensing satellites to promote the transformation and upgrading to real-time intelligent ***,based on the three imaging systems of the optical mapping and remote sensing satellites and their realization methods and application characteristics,this paper analyzes the applicable system of the intelligent mapping and remote sensing ***,according to the application requirements of real-time,intelligence,and popularization,puts forward the design concept of integrated intelligent remote sensing satellite integrating communication,navigation,and remote sensing and focuses on the service mode and integrated function composition of intelligent remote sensing *** expounds on the performance and characteristics of the Luojia-301 satellite,a new generation of intelligent surveying and mapping remote sensing scientific test *** finally summarizes and prospects the development and mission of intelligent mapping remote sensing ***-301 satellite integrates remote sensing and communication *** explores an efficient and intelligent service mode of mapping and remote sensing information from data acquisition to the application terminal and provides a real service verification platform for on-orbit processing and real-time transmission of remote sensing data based on space-ground internet,which is of great significance to the construction of China’s spatial information network.

关键词： real-time intelligent services collaborative application on-orbit processing mapping and remote sensing information Luojia-301 satellite

Sources, distribution, behavior, and detection techniques of microplastics in soil: A review

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China Geology 2023年第4期6卷 695-715页

作者： Yu-chen Yan Zhong-fang yang School of Earth Sciences and Resources China University of GeosciencesBeijing 100083China

In recent years, the problem of environmental pollution caused by microplastics has attracted widespread attention. This paper reviews the latest research progress in terms of the source, content and distribution characteristics, harm, and detection technology of soil microplastics by referring to the relevant literature on soil microplastics worldwide. It concludes that:(1) Existing studies worldwide have detected the presence of microplastics in soil, water, and atmosphere, and the use of agricultural films, sewage sludge,and other man-made activities are the main sources of microplastics in soil;(2) microplastics can adsorb heavy metals, persistent organic pollutants and antibiotics in soil, change the physical and chemical properties of soil. This will result in composite pollution and harm to the ecosystem;(3) microplastics in soil not only can destroy the activity of key soil microorganisms, but also enter the body of crops and soil animals, affecting normal growth of crops and soil animals, and further threaten human health;(4) at present, there is no unified operating standard for the sampling, processing, and detection process of microplastics. Analysis methods such as visual inspection, spectroscopy, and thermal analysis have both advantages and disadvantages, and emerging detection technologies require urgent *** have become a new pollutant in soil and their distribution characteristics are closely related to human activities. They pollute the environment and threaten human health through the food *** related research on soil microplastics has just begun, it will become the focus of research in the future.

关键词： soil microplastic heavy metal organic pollutant antibiotic microorganism ecological risk composite pollution detection method

Validity of Different Methods to Prenatal Screening for Down’s Syndrom During First and Second Trimester Pregnancy of Chinese Women

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Biomedical and Environmental Sciences 2013年第2期26卷 87-93页

作者： yang fang WANG Hua SHI Jing Cheng HU Ming Department of Epidemiology and Biostatistics School of Public HealthCentral South University Department of Molecular Biology School of Bioscience and TechnologyCentral South University Center of Prenatal diagnosis Maternal and Child Health Hospital of Hunan Province

Objective To identify and determine the optimal method to screening for fetal Down＇s syndrome （DS）. Methods Three large cohorts with 17 118, 39 903, 16 646 subjects were enrolled for the first trimester double marker （pregnancy-associated plasma protein A and free [B-human chorionic gonadotropin） screening （FTDMS）, second trimester double marker （c{-fetoprotein and free B-human chorionic gonadotropin） screening （STDMS）, and second trimester triple marker （a-fetoprotein, free 13-human chorionic gonadotropin and unconjugated estriol 3） screening （STTMS）, respectively. The sensitivity, specificity, false positive rate （FPR）, false negative rate （FNR） and the areas under ROC curves （AUCs） were estimated in order to determine the optimal screening method in women under or above 35 years old. Results For women under 35 years old, STTMS was the best method with a detection rate of 68.8% and FPR of 4.3% followed by the STDMS with a detection rate （sensitivity） of 66.7% and FPR of 4.9%. The FTDMS had a lower detection rate of 61.1% and FPR of 6.3%. For women above 35 years old, the detection rate of all the methods was similar, but STTMS method had a lowest FPR of 15.9%. For women under 35 years old AUCs were 0.77 （95% CI, 0.64 to 0.91）, 0.81 （95% CI, 0.71 to 0.91）, and 0.82 （95% CI, 0.69 to 0.96） for FTDMS, STDMS, and STTMS methods, respectively; for those above 35 years old, AUCs were 0.70 （95% CI, 0.56 to 0.83）, 0.70 （95% CI, 0.59 to 0.82）, 0.78 （95% Cl, 0.58 to 0.97） for FTDMS, STDMS and SITMS, respectively. Conclusion Findings from our study revealed that STDMS is optimal for the detection of fetal DS in pregnant women aged under 35. For individual women, if economic condition permits, STFMS is the best choice, while for women aged above 35, STTMS is the best choice in this regard.

关键词： Prenatal screening Down's syndrome First trimester, Second trimester Marker

Lane-changing trajectory prediction based on multi-task learning

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Transportation Safety and Environment 2023年第4期5卷 67-77页

作者： Xianwei Meng Jinjun Tang fang yang Zhe Wang Smart Transport Key Laboratory of Hunan Province School of Transport and Transportation EngineeringCentral South UniversityChangsha 410075HunanChina

As a complex driving behaviour,lane-changing(LC)behaviour has a great influence on traffic *** lane-changing behaviour often leads to traffic *** studies are currently being conducted to predict lane-change trajectories to minimize ***,most of their models focus on how to optimize input variables without considering the interaction between output *** study proposes an LC trajectory prediction model based on a multi-task deep learning framework to improve driving ***,in this work,the coupling effect of lateral and longitudinal movement is considered in the L.C *** changes in two directions will be modelled separately,and the information interaction is completed under the multi-task learing *** addition,the trajectory fragents are clustered by the driving features,and trajectory type recognition is added to the trajectory prediction framework as an auxiliary ***,the prediction process of lateral and longitudinal trajectory and LC style is completed by long short-term memory(LSTM).The model training and testing are conducted with the data collected by the driving simulator,and the proposed method expresses better performance in LC trjectory prediction compared with several traditional *** results of this study can enhance the trajectory prediction accuracy of advanced driving assistance systems(ADASs)and reduce the traffic accidents caused by lane changes.

关键词： lane-changing behaviour trajectory prediction long short-term memory(LSTM)network multi-task learning trajectory clustering